Yaesu FT-70D Chirp Programming on a Mac

It works but it's not a lot of fun.  Better than typing in 40+ channels from the keypad though.  If you just have a few repeaters to punch in, you're probably better off doing this from the keypad.  Here's the how-to on that.

First, watch Wiredhand's excellent video: https://www.youtube.com/watch?v=bnS2rH8kp40  Seeing the motions will help you with the flow of this project before actually diving in and doing it.

Here are the steps:

1. Open Chirp.
2. Turn radio on.
3. Unclip the battery – don't take it out, slip it slightly up & off the contacts.  You'll want to be able to push it back in in the next step.
4. Hold PWR & AMS key, then slide & clip battery back in.  Radio display should show "ADMS"
5. Stand up, raise your hands straight up, and twirl around three times while humming the Oscar Meyer theme song.  This doesn't do anything, but it makes about as much sense as those previous two steps.  What idiot designed this UI?
6. Plug in USB cable.  Use the one that came in the box, and no others.  On the Mac end, plug directly into a USB port, not into any of those Lightning/USBC-to-USB adapters.  Don't have a free USB port?  Clear something out.  No adapters!!  And no capes!! either.
7. In Chirp menus, go to radio > download.  Hit OK.
8. On the radio, hit the Band button.  Display should change to "TX"   You should see a progress bar "cloning from radio"
9. Save a copy of the original blank memories under a separate name.
10. Edit channels as desired.
11. In Chirp menus, go to radio > upload  – do not hit OK yet.
12. On the radio, be ready on the Mode key.  Hit Chirp's OK, then Mode quickly afterward.  Upload should commence.
13. When done, unplug cable and cycle the power on the radio.  It should be good to go.

It's a pretty weird set of steps alright.  It may take you a couple of tries, especially on #4, but it does work.

Good luck.